Field of the Invention
The present invention includes a method of preparation of a hair treatment formulation comprising nanoparticles in solution which are specifically structured such that one or more preselected hair treatment components may be embedded therein. The nanoparticles are prepared having a range of pH values which, in conjunction with the pH values of the carrier solution itself, effect the opening and closing of the hair cuticles, and thus, the delivery and retention of the embedded hair treatment components therein. The present invention further comprises a method for treatment of a user's hair utilizing a solution of specifically structured nanoparticles having one or more treatment components embedded therein.
Description of the Related Art
Hair is made from proteins that have a special structure forming long extended fibers with very good mechanical properties. The hair shaft comprises an outer protective layer of layered scales known as the cuticle layer. This cuticle layer has tiny elongated scales that overlap to form a covering around the hair shaft and this covering can open to allow access into the inner areas of the hair shaft. The cuticle layer is hydrophobic and does not get saturated with water and other chemicals and it is made from cysteine, an amino acid found in many proteins in the body that form very hard strong matrices that have very good mechanical properties. Below this outer cuticle layer of scales is a layer of the cuticle structure that is very rich in cysteine proteins called the exocuticle. This layer comprises about 37% of the total cysteine protein content of the cuticle layers.
Just below the cuticle layer is a column of cells called the cortex. The cortex is made up a rigid network of strong cells and is mechanically the most important structure that controls the tensile strength, flexure, and shape of hair fibers. These cells are large and elongated and are aligned along the axis of the hair shaft forming the rigid network. This rigid network of cells is primarily made from cysteine proteins and other amino acids held together by disulfide bonds. The disulfide bond is a covalent chemical bond binding two sulfur atoms together. As the hair grows, it builds structural meshes of covalently bound cysteine proteins forming the general fiber shape of the hair. The shape of the fiber is determined by the manner in which the network of disulfide bonds is formed along the hair shaft. Kinks and bends occur as the general shape that the hair shaft takes for minimal stress from the forces of the disulfide bonds. Modifying this cellular structure by weakening the covalent bonds and de-stressing the hair fiber is the main method that has been used to straighten hair in the past.
Many existing hair smoothing, straightening and conditioning cosmetic formulations use very harsh and environmentally unfriendly chemicals such as high concentrations of formaldehyde, glutaraldehyde, thioglycolic acids and other very unfriendly chemicals. The chemistry of these existing formulations depend upon breaking covalent disulfide bonds and/or charged ionic exchanges that bind conditioning agents to the hair cuticle.
In lye based systems, a strong base, such as sodium hydroxide or lithium hydroxide, is used at a high pH of about 11 to 12, to sever the covalent bonds of the cysteine proteins in the cortex region and recreate these bonds in a relaxed structure of the cortical cells. This process is like taking a structure made from strong beams and reshaping it by reconnecting the beams in a new way. The repeated restructuring of disulfide bonds of the cortical cysteine amino acids can result in substantial damage to the hair over time since the disulfide bonds are broken off completely, and cysteine may be continuously lost as cysteic acid through this process. This loss of cysteine can make the hair age fast and become dull, brittle and weak, leaving the hair dry and unmanageable.
In another system called a perm, also referred to as the non-lye systems, thioglycolic acid and acetic acid mercapto-monoammonium salts are used at a pH of about 8 to 9, to restructure the disulfide bonds of the cortex in a permanent fashion. This system provides a reshaping treatment that is permanent, and can only be grown off by new hair growth, as the hair proteins are modified completely so that they cannot be reversed back to their normal original state. Further, two steps are generally needed for the perm process, and a secondary oxidation phase using a peroxide that stops the disulfide exchange reaction is necessary to stop the reaction of thiolate on the cysteine proteins otherwise the hair will eventually break and fall off completely. These systems also require a set period of application of the solution on the hair so that the amount of interchange of disulfide bonds can be limited, otherwise, once again, the hair will break and fall off.
In the so called “Brazilian” based system, formaldehyde is used to react with the cysteine of the hair, such that the hair cysteine and the formaldehyde will eventually degenerate into a thiazolidine carboxylic acid with very good, although temporary, hair conditioning qualities. Repeated applications via this method will eventually cause a lot of cysteine proteins from the hair itself to be trapped as detached carboxylic acids and hence will depart from the hair as lost proteins, leaving the hair pitted and damaged over time.
In yet another system called the “Keratin Complex” systems, timonacic acid, a thiazolidine 4-carboxylic acid, and its derivatives, are used. In this system of hair renewal and rejuvenation, timonacic acid, which is a condensate of cysteine and formaldehyde, is used as an active agent. This system utilizes the opening of the thiazolidine ring to deliver cysteine proteins to the hair using disulfide bonds. The system works by donating cysteine from keratin proteins and from the thiazolidine or timonacic molecule to the hair, while maintaining a constant supply of keratin proteins to react with the carboxylic groups that result from the donation.
Thus, to modify hair, one must weaken and break the disulfide bonds of the cortex and allow the proteins to realign into a desired shape and then relock the bonds into the new shape desired by thermal processes or oxidation setting. In almost all of these systems, a high concentration of formaldehyde or a carboxylic acid is required to interact with the sulfide bonds and cleave these bonds for introducing new structure to the hair during ironing.
Unfortunately, the dangers associated with the release of formaldehyde and the controversy of whether hydrated formaldehyde in the form of methylene glycol is acceptable in cosmetic products, has not been resolved by the governing bodies that oversee cosmetic products. In fact, in most countries of the world, the use of chemical releasing agents of formaldehyde is restricted to a concentration of 0.2% free formaldehyde in the total solution content.
Though effective, HPLC or high-pressure liquid chromatography, a chromatographic testing technique used by governing bodies to determine the formaldehyde content of cosmetic solutions, has been shown to actually break open the timonacic ring and scavenge the carboxylic group from the molecule to measure formaldehyde as a positive result in the cysteine complex products. Further, the Brazilian systems use raw formaldehyde at a very high concentration, and so, a lot of controversy has been directed at most existing products even though some, like cysteine complex products, do not use formaldehyde in its free form.
None of the known systems utilize nanoparticle technology to encapsulate their active chemical components, rather, known systems are all based on homogenous chemical solutions and blends that are applied to the hair directly.